Contact-interrupter for the electromagnetic production of musical sounds.



A. H. MAITRE & V. II. 6. MARTIN.

CONTACT INTERRUP'IER FOR THE ELECTROMAGNETIC PRODUCTION OF MUSICAL SOUNDS.

- APPLICATION FILED MAR- 27. I914- 1,249,15 7. Patented Dec. 4,1917

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III HIIII IIIIIII III! III I IIIII IIIIII gdfi III!!!IIIIIIIIIIII II IIIIIIIIIIII WITNESSES IIYVEIYTORS 9-6 ALCIDE HECTOR ITRE IICTOK HENRI Gmsro ARTIN ATTORNEYS A. H; MAITRE & V. H. G. MARTIN- 7 CONTACT INTERRUPTER FOR THE ELECTROMAGNETIC PRODUCTION OF MUSICAL SOUNDS. APPLICATION FIL'ED MAR. 27. 1914.

1,249,157. Patented Dec. ,4, 1917.

3 SHEETS-SHEET 2- IIIIIIIIIIIIIIIIIIIIIII g v c H INYEWTOKS ALCIDE HEQT K MAITRE YICTOK HENRI GASTON MARTIN ATTORNEYS v A. H. MAITRE 8i V. H.'G. MARTIN. 3 CONTACT INTERRUPTER FOR THE ELECTROMAGNETIC PRODUCTION OF MUSICAL SOUNDS.

APPLICATION FILED MAR. 27,1914- 1,249,157. Patented Dec. 4,1917.

3 SHEETS-SHEET 3- //V VENTORS UNITED STATES rnrnntr I oFFroE.

ALCIDE nno'ron Merriam AND VICTOR HENRI GASTON MARTIN, or noUEmrRANoE.

oonrnor-mcrnnnor'rrm roe THE ELECTROMAGNETIC PnoDUo'rIoN or MUSICAL SOUNDS.

Specification of Letters Patent.

Patented. Dec. 4, 1917.

, Application filed, Mar-ch 27, 1914. Serial No. 827,656.

The present invention relates to contact breaker devices in which one of the contact pieces is carried by a movable arm mounted on a pivot or on a spring in such a way as to be able to take up a vibration of small amplitude.

It is characterized by the fact that the movable contact piece is formed by a bundle of line non-oxidizing wires more or less twisted and fitted in a small portion of a soft body such as caou tchouc, while the other contact piece is subjected to the vibrations of the sonorous element.

This device has for object to damp out false vibrations and to suppress all noise, so as to give a pure sound.

The invention is described in its application to the setting in vibration of the strings of a piano, but it covers the setting in vibration of all bodies.

The annexed drawings represent by way of example, several forms of construction of the object of the invention.

Figures 1- and 2 are side elevations of a contact mechanism in which the contact plate a is operatively connected to the sonorous element by spring F which carries the contact and the'bent end of which. rests upon the vibratory string A;

Fig. 3 is a diagrammatic representation of the electrical connections of the arrangements of Figs; 1 and 2 for a group of two electro-magnets;

Fig. 4 is a View similar to those of Figs. 1 and 2 but showing a modification in which the vibrating contact a 'is curved to present its side, instead of its end, toward the cooperating contact 0, and the electro-magnet E is arranged on the same side of the sonorous member A as the contact interrupter. V

Fig. 5 is a partial side elevation showing a modified contact a the vibrations of which are at right angles to those of the sonorous element A: 6 is a s milar View, but showi g a cated.

modification in which the contact a is carried by a lever A engaging the sonorous element A and vibrating therewith, but so arranged that contact 11 moves in one direction when the sonorous element A moves in the opposite direction.

Fig-7 is a front elevation, drawn to a larger scale, of the arrangement shown in Fig. 6; and

Fig. 8 1s a s de elevation of a f urther' modification showing the contact a operatlvely connected to the sonorous element A through a filament F. j

In the arrangement shown in Fig. 1, the contact piece a is subjected to the vibrations of the string A by means of a spring F which carries the contact piece and the end of which is angled into engagement with the string A. A counter spring F bears on spring F through a soft pad, such as rubber, to augment the, pressure of spring F on the cord and to prevent noise in the operation. of the contactmechanism. 0 is a non-oxidizingcontact-piece formed by a bundleof fine wires, suitably twisted, and fitted in a soft body such as rubber D itself gripped between the two arms (Z of afork mounted upon the movable arm C; a small piece of sheet metal G bent to U-shape holds together the two arms of the fork. One-of the ends of the flexible wire 0 bears upon the contactpiece a, the other end ofthe wire 0 is folded between the rubber and one of the arms (Z of the fork to establishthe electrical connection of c with-the movable arm C-and therefore with the support H. The latter is a copper fork, between the arms of which is pivoted the shaft 0; c is an electromagnet inserted in the circuit of the electromagnet E actuating the string and exerting its attractive force upon the armature g to separate the contacts 0 a. L is a spring controlling the pressure of the contacts '0 a. The upper end of the movable arm C terminates in a circular arc 11 upon which the flywheel 1 presses its spindle 2 so as to damp the oscillations of C. B is a transverse insulating rod-upon which are fixed the springs F F; N is a transverse insulating bar supportin the contacts by means of an adjusta- .ble knee M; V

In Fig. 3 the electrical connections for a group of two electro-magnets E are. indi- Vhen the interrupter I is closed, the

current flows through the electro-magnet E,

interrupter I, electro-magnet e, clamp frame H, spindle c, pivoted arm C, clamp d, contact pieces 0 and a, spring F and thence to its source.

The operation of the interrupter mechanism and electro-magnet e is readily understood from our Patent 1,106,230, while our co-pending application Serial No. 819,602, filed Feb. 18, 1914:, describes the clamping device.

In the remaining figures the same letters indicate like organs. In Fig. 2, which shows the mechanism for treble notes, the contact piece a is subjected to the vibrations of the sonorous member A by a cylindrical steel spring bearing against the member A. The cooperating Contact 0 is in the form of a wire the end of which bears against the plate a. C' is an adjustable counterweight regulating the pressure of the contacts c a. The whole of the parts, includ ing the springs F and F, are carried upon a metal plate M forming a bridge between the transverse rod B and the transverse bar N. The working is the same as in Fig. 1.

Fig. 4 represents an arrangement without damping device, applied to a low note.

The electromagnet E is in front of the strings as is the contact 0 a itself; the electromagnet 6 works by attraction, being placed in shunt to the contacts c a. The counter weight 0 tends to separate the contacts 0 a with an adjustable force; the armature g is connected to the movable arm C by means of a piece of rubber g fitted in a fork riveted upon C.

It is evident that in the three preceding figures, the flat spring F might have been replaced by a steel wire having the same profile but hooking around the string instead of pressing upon it. I Fig. 4: shows how the contact piece a can be rendered integral with the string by a metal or other wire or thread F or by a rigid rod passing through perforations F in the wrest-plank and allowing of placing the contacts 0 a on the opposite side to the string in relation to the wrest-plank and in two rows;

It is evident also that a very, short wire can be used to connect the spring F to the string.

In Fig. 5 the contact piece a is formed by a rigid non-oxidizing knee-piece, fixed to the root of the spring F in such a way as to avoid all false vibration whichthespring F might produce in its non-rigidpart.

In Figs. 6 and 7, the direction of vibration is reversed through a small lever A having its axis at A A spring F forces the recurved end of the lever against the string A, which engages in a notch a in the lever end. A notch in the engaging edge of the spring F prevents the lever A from becoming laterally displaced;

Fig. 8 shows the contact pin a operatively connected to the string A by means of a filament F of any suitable character, extending through the bor F 3 in the frame between the contacta'and the sonorous string A.

We claim 1. A contact device of the type described, comprising a pair of cooperating vibratory contacts, a member riding a vibratory operating element and operatively connected to one of said contacts, one contact of the pair comprising a bundle of twisted, fine nonoxidizing wires.

2. A contact device of the type described, comprising a pair of cooperating vibratory contacts, a member riding a vibratory operating element and operatively connected to one of said contacts, one contact of the pair comprising a bundle of twisted, fine nonoxidizing wires mounted in a sound-deadening support.

3. A'contact device of the type described, comprising a pair of cooperating vibratory contacts, a member riding a vibratory operating element and operatively connected to one of said contacts, one contact of the pair comprising a bundle of twisted, fine nonoXidizing wires mounted ,in a rubber support.

4. A contact device of the type described comprising a pair of cooperating vibratory contacts, a member recessed to ride a vibratory member and operatively connected to one of said contacts, the other contact comprising a bundle of fine non-oxidizing wires.

5. A contact device of the type described comprising a pairof cooperating vibratory contacts, a member recessed to ride a vibratory member and operatively connected to one of said contacts, and an independent spring pressing said member into engagement with said vibratory member.

6. A contact device ofthe type described comprising a pair of coiiperating vibratory contacts, a rigid lever member recessed to ride a vibratory member and carrying one of said contacts, and an independent spring pressing said lever into engagement with said vibratory member.

In testimony whereof we sign our names to this specification in the presence of two subscribing witnesses.

ALCIDE HECTOR mirlni. VICTOR HENRI GASTON MARTIN. lVitnesses:

LoUIs Conoucn, LUCIEN MEMMING R.

Copies of th is patent may be obtained for five cents each, by addressing the Qo nmissjoner of Eatents,

Washington, D G. 

